1. Field of the Invention
The present invention relates to a solid nonimaging lens capable of both (a) redirecting the generally parallel light rays of a directional light beam as desired by means of a first refraction followed by a total reflection and eventually a second refraction, and (b) concentrating light rays into a generally directional light beam by means, eventually of a first refraction, followed by a total reflection and a second refraction.
2. Brief Description of the Prior Art
Nonimaging lenses consisting of a solid body of light-propagating material have been widely used in the past to control dispersion of light.
For example, the nonimaging lens of U.S. Pat. No. 2,908,197, granted to W. B. Wells et al. on Oct. 13, 1959, uses a total reflection followed by a refraction to control the dispersion of the light rays generated by an omnidirectional light source.
U.S. Pat. No. 4,521,835 (Meggs et al.) issued on Jun. 4, 1985, discloses a double refraction to control the dispersion of omnidirectional light rays emitted from a plurality of light-emitting diodes (LED's).
LED's capable of emitting a generally directional light beam of high luminous intensity, such as the LED HLMP 8100 manufactured and commercialized by the company Hewlett Packard, have been developed and are now available on the market. Obviously, the lens of Wells et al. and Meggs et al., designed for omnidirectional light sources, are inefficient when one wishes to obtain a specific pattern of dispersion of the generally parallel light rays of a directional light beam.
A new generation of lenses is accordingly required to enable efficient application of these high intensity LED's to various fields.